We wrote Exploring Geology so that students could learn from the book on their own, freeing up instructors to teach the class in any way they want. I (Steve Reynolds) first identified the need for this book while I was a National Association of Geoscience Teachers’ (NAGT) distinguished speaker.

My purpose in writing this book is to describe my own experiences, from my graduate student days in the 1950s to the present (2001). when I came upon phenomena or facts that did not support the prevailing ideas and theories, or even contradicted them. In some instances, the encounters began with nothing more than the naive questions I posed as a graduate student to my professors regarding a well-established fact: others were the result of questions my graduate students asked me. Essentially, this is an account of my personal encounters with some of the ideas and theories that once prevailed but were later eliminated in the history of auroral science. I believe that young researchers becoming successful as scientists depends on how they deal with new phenomena or facts that do not fit established theories. One cannot be a researcher unless he/she can encounter such a problem. This is because such ;ui encounter is the very first step for new progress. When encountering such problems, some may put the discordant facts on the shelf or sweep them under the rug. so to speak, at least for a while. Others may try hard to find a way to make new facts fit into prevailing ideas by modifying or improving them. Yet others may try to establish a new idea, scheme, or theory by adapting their findings and those of others, but abandoning the prevailing interpretation of the phenomena or facts. It has been my experience that it is the people in this last group who produce epoch-making progress in science. The choice of what to do when facing this situation is not easy and depends on many factors, lirst of all. researchers have to know where they stand at that point in the history of their scientific discipline. It is therefore crucial to have a deep historical knowledge of the background of a prevailing idea or the established interpretation of a phenomenon. To choose a course of action without knowing the background would be like starting to run in the dark without a sense of direction or of the surroundings. Unfortunately. I see too many young scientists doing just that, particularly those who believe that technological advance is everything. Often, a mentor provides the history, not necessarily in a classroom setting, but through daily interactions. I was fortunate to have a very good mentor. Sydney Chapman, who guided me during my early days.

The Ivrea crustal cross-section (northern Italy and southern Switzerland) (Andre Zingg)
The exposed crustal cross section of southern Calabria, Italy: structure and evolution of a segment of Hercynian crust (Volker Schenk)

An exposed cross-section of continental crust, Doubtful Sound Fiordland, New Zealand; geophysical & geological setting (G.J.H. Oliver)
Uplift and exhumation of middle and lower crustal rocks in an extensional tectonic setting, Fiordland, New Zealand (G.M. Gibson)

The great conservationist E. O. Wilson called the love of nature, and especially the love of biodiversity, biophilia. He had in mind not only our love of the outdoors, of nature, of getting away from our hurried, technological world, but also a fundamental justification for wildlife conservation. Why should we prevent species from going extinct? We could make economic arguments and say that we get useful products such as food and drugs from many plants, or that natural habitats keep the Earth’s energy flows, oxygen and carbon in balance. But Wilson was keen to remind us that purely economic arguments are not enough, or they can be used misleadingly. His point was that we should love biodiversity, the richness and colour of all living things, and humans (or any other species) have no right to kill off all members of another species.